4 research outputs found

    Control of Automatic Food Drive-Through System using Programmable Logic Controller (PLC)

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    This project is about automatic control for food drive through system controlled via Programmable Logic Controller (PLC) and this system consists of food drive through with two lanes and no human operator is required to operate this food drive through. The difference of this automatic control drive through system compared with the current drive through system is the current system required a few operators to operate the system. This automatic control drive through system is fully operated by machine, like order and payment machine and conveyor which deliver the food while human only needed and involved only to prepare the food. Since there are two lanes involved in this system, the machine installed has two order and payment machines, two ticket verification machines, two conveyors which connect to the kitchen and four sensors to detect the vehicles

    Improved Internet Security Protocols Using Cryptographic One-Way Hash Chains

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    In this dissertation, new approaches that utilize the one-way cryptographic hash functions in designing improved network security protocols are investigated. The proposed approaches are designed to be scalable and easy to implement in modern technology. The first contribution explores session cookies with emphasis on the threat of session hijacking attacks resulting from session cookie theft or sniffing. In the proposed scheme, these cookies are replaced by easily computed authentication credentials using Lamport\u27s well-known one-time passwords. The basic idea in this scheme revolves around utilizing sparse caching units, where authentication credentials pertaining to cookies are stored and fetched once needed, thereby, mitigating computational overhead generally associated with one-way hash constructions. The second and third proposed schemes rely on dividing the one-way hash construction into a hierarchical two-tier construction. Each tier component is responsible for some aspect of authentication generated by using two different hash functions. By utilizing different cryptographic hash functions arranged in two tiers, the hierarchical two-tier protocol (our second contribution) gives significant performance improvement over previously proposed solutions for securing Internet cookies. Through indexing authentication credentials by their position within the hash chain in a multi-dimensional chain, the third contribution achieves improved performance. In the fourth proposed scheme, an attempt is made to apply the one-way hash construction to achieve user and broadcast authentication in wireless sensor networks. Due to known energy and memory constraints, the one-way hash scheme is modified to mitigate computational overhead so it can be easily applied in this particular setting. The fifth scheme tries to reap the benefits of the sparse cache-supported scheme and the hierarchical scheme. The resulting hybrid approach achieves efficient performance at the lowest cost of caching possible. In the sixth proposal, an authentication scheme tailored for the multi-server single sign-on (SSO) environment is presented. The scheme utilizes the one-way hash construction in a Merkle Hash Tree and a hash calendar to avoid impersonation and session hijacking attacks. The scheme also explores the optimal configuration of the one-way hash chain in this particular environment. All the proposed protocols are validated by extensive experimental analyses. These analyses are obtained by running simulations depicting the many scenarios envisioned. Additionally, these simulations are supported by relevant analytical models derived by mathematical formulas taking into consideration the environment under investigation

    Evaluaci贸n ambiental de un tramo espec铆fico de la autopista Panamericana Sur, usando la metodolog铆a de an谩lisis de ciclo de vida

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    La construcci贸n, mantenimiento y operaci贸n de la infraestructura vial en el mundo constituye un foco relevante del impacto ambiental, debido a los usos de materias primas y combustibles f贸siles ligados a ellas. Mientras que la red vial en muchos pa铆ses europeos y norteamericanos tuvo un crecimiento importante en las 煤ltimas d茅cadas del siglo pasado, este auge se est谩 viviendo en la actualidad en el Per煤. En base a esta circunstancia, cada vez es m谩s importante conocer cu谩les son los impactos ambientales que se generan durante la construcci贸n, mantenimiento y operaci贸n de estas infraestructuras. Por ello, se ha realizado una evaluaci贸n ambiental aplicando la herramienta de An谩lisis de Ciclo de Vida, con el fin de determinar los impactos ambientales ligados a un tramo de la Panamericana Sur en el sur de la provincia de Lima. Se evaluaron las etapas de construcci贸n, uso y mantenimiento, a partir de una unidad funcional de 1 kil贸metro de carretera en 1 a帽o de operaci贸n. Para aplicar el ACV se utiliz贸 la metodolog铆a ISO 14040 y se emple贸 la informaci贸n primaria entregada por la empresa concesionaria durante la etapa de estudio como mediciones in situ y metrado de planos. Adem谩s, se us贸 informaci贸n secundaria procedente de bases de datos internacionales para complementar la informaci贸n restante y se model贸 la emisi贸n del material particulado. Se evaluaron indicadores de impacto ambiental como el cambio clim谩tico, el agotamiento de combustibles f贸siles y otras materias primas, emisiones de material particulado, entre otros. Se utiliz贸 la metodolog铆a de c谩lculo IPCC 2013 para cambio clim谩tico y ReCiPe para las dem谩s categor铆as estudiadas. En lo que refiere a los resultados, la etapa de uso representa un 99% del impacto total en todas las categor铆as de impacto. En lo que se refiere al cambio clim谩tico, se revel贸 que se producen 8 302 toneladas de CO2eq por kil贸metro de carretera producto del alto flujo vehicular que utiliza esta v铆a de acceso a la capital. Por otro lado, el 1% restante corresponde a la construcci贸n y mantenimiento de la v铆a. Adicionalmente, la formaci贸n de part铆culas represent贸 una importante fuente de impacto debido a las emisiones del veh铆culo en contacto con la carretera, la resuspensi贸n del material en la superficie y el desgaste de los frenos. Finalmente, se analizan distintos escenarios alternativos y su impacto ambiental en contraste con el escenario base. Adem谩s, tambi茅n se realiz贸 una comparaci贸n entre el escenario base y distintas investigaciones existentes en pavimentos en donde se obtiene que los resultados est谩n en un mismo rango. Sin embargo, dicha comparaci贸n demuestra que la autopista analizada es la que presenta un mayor porcentaje de impacto durante su etapa de uso. Por 煤ltimo, los inventarios, resultados y an谩lisis realizados en esta tesis podr铆an ser de gran ayuda para la elaboraci贸n de futuros proyectos de obras viales en el terreno costero nacional.Tesi
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